The germination of dormant spores may be used as a convenient experimental system for study of mitochondrial biogenesis and for study of the cooperation between the nuclear and mitochondrial genetic systems for the organization of the mitochrondrial respiratory membrane. Dormant spores of the mycelial fungus Botryodiplodia theobromae have mitochondria which are structurally incomplete and incompetent in respiration. Nevertheless, the germinating spores have an essential requirement for a functional mitochondrial respiratory system. The general objective of this research project is to learn how two of the missing respiratory enzymes, cytochrome c oxidase and ATPase, are rapidly assembled into the mitochrondrial membranes early in germination. The role of the preserved nuclear mRNA of the dormant spores in the development of these respiratory enzymes will be examined through in vitro translation and immunoprecipitation with enzyme-specific antisera. Experiments will be performed to establish how the cytoplasmically synthesized peptide subunits of these enzymes are transported into the mitochondria and to learn whether the mitochondria of dormant spores possess a transport-processing system for these imported enzyme subunits. Studies will be performed with spores of Neurospora crassa to establish how the respiratory system (and especially cytochrome c oxidase) is assembled early in spore germination.